Magneto-electric machine for internal-combustion engines



c. c.` PUCKETTE.

MAGNETO ELECTRIC MACHINE FOR INTERNAL -COMBUSTION ENGINES.

APPLlATloN FILEDv MAY 4. |920.

1,419,076. Y Patentd June `6, 1922.

UNITED 4STATi='..s

PATENTv OFFICE.,

CHARLES c; rUcxE'r'rE, or SALFORD, ENGLAND, AssreNoa on (SNE-HALE To coNNEnl MAGNETO a IGNITroN, LIMITED, or s'roxE, WARWICKSHIRE, ENGLAND.

MAeNEro-ETLECTEI MACHINE ron iNfrnaNAL-cormnsrroiv ENGINES.

Specification of Letters Patent. Patented June 6, 1922.

Application flied May 4, lazo. serial Nu. 378,878;

To all w imm t may concern Be it known that I, CHARL-Es CLARKE PUCKETTE, a citizen of the United States ot America, and resident of Peel Works, Adelahi, Salford, in the county of Lancashire,

ngland, have invented certain new and useful Improvements lin Magneto-Electric Machines for Internal-Combustion Engines (for which I have obtained patents in Great Britain, No. 136,705; in Germany, No. 333,456, and in France, No. 515,203), of which the following is a specification, such as will enable others skilled in the art to which it appertains to make and use the same. y ,v

My invention relates to improvements in magnetos for ignition purposes, of the type having extensions or horns at the leading edges of the poles. Such machines while giving fairly good sparking at the fully retarded position of the engine, that is, when the contact breaker is opened as the trailing edges of the armature are leaving the polar extensions, and also at the fully advancedr position, that is, when the trailing edges of the armatures have not reached the base of the extensions, yet with high speeds at the fully advanced position the sparking is liable to become erratic and ineilicient; because if the polar horns are of suiiicient cross sectional area to allow of good sparking when the armature is running slowly at the fully retarded position, then at the high speed running at the advanced position, the main field, in consequence of armature reaction is so distorted as to saturate the polar horns.

The object of the present invention is to overcome this defect, which is accomplished by the means now set forth.

I make the polar extensions of ample cross sectional area to ensure that strong sparks are obtained at low armature speeds with the magneto fully retarded, and in order to prevent the armature reaction distorting the main field at high armature speeds, we provide the polar extensions with shading or amortisseur coils, that is, short circuited conductors surrounding the said extensions or which are embedded therein.

Fig. 1 oi the accompanying' drawings is an end elevation of a pair of polar pieces showing polar extensions each with a shading coil thereon; Fig. 2 is an inside plan of the upper pole-piece', and Fig. 3 is a side elevation of same.

Fig. 1 is an end elevation of a modified construction.

Fig. 5 is a plan of the same.

The coil is indicated by A and consists of a band of copper, aluminium, or other suitable conductor, and it is placed at or near the base of a horn B of ay poleepiece or at any7 other suitable position, and as will be seen, it forms a short circuited conductor of low resistance surrounding the horn B. More than one coil may be arranged in similar manner around a pole horn. Figs. 4 and 5 show pole-pieces and horns embedded in the body of the magneto which is cast about or around the said parts to form an integral structure or unit with them. In this case the metal which enters the grooves D which is of course united to the main casting E (indicated in dotted lines in the last three ligures) forms with it short circuited conductors around the horns B. Or the grooves D may each have a copper or like rod, coated at its ends with suitable solder, placed through it, to which the casting material would unite and together form short-circuited conductors around the horns. v

The effect of the currents induced in the coils or short-circuited conductorsy is to react on the main field fiux, preventing its distortion by armature reaction; concentration of magnetic flux at the tips of the polar extensions is thus avoided, so that at the high est speeds at the fully advanced position, good sparking is obtained. It will thus be seen that the object and the action of my device are diii'erent from an arrangement previously proposed in"` which a short cir-- cuited coil is placed round the whole of the pole-pieces.

What I claim and desire to secure by Letters Patent is: n

1. In a magneto ignition apparatus with pole pieces having extensions to form polar horns at the leading edges of the poles, and

shading coils placed around the polar horns to prevent the distortion of the main field flux by armature reaction and the consequent concentration of the magnetic flux at the f tips of the polar extensions.

2. In a magneto ignition apparatus with pole pieces having extensions to form polar horns at the leading edges of the poles only, and shading coils placed around the polar horns to prevent the distortion of the main eld flux by armature reaction and the consequent concentration of the magnetic flux :1 metal rod about the extensions at the lead- :it the tips of the politi extensions. ing edges of the poles and partly by the inag- A magneto ignition apparatus ineludneto body. ing a body having extensions at the leading In Witness whereof I have hereunto set my 5 edges of the poles, and means for the prevenhand in presence of two Witnesses.

tion Ol: the; dStOl-Jlon Of the field flllX C by :i1-mature reaction and the consequent coneentration of the magnetic linx at the tips of lVitnesses:

the pole extensions, said means consisting of 7. LANDERZ, 10 :t short eircuited conductor formed partly of FRANK HILL. 

